Commercial signs are a well-known method by which businesses advertise their services. For example, many businesses will have a sign located on their premises that advertises the name of the business, the hours of the businesses, prices, and other information pertinent to the business's customers. Past commercial signs have relied on standard electrical service for power. In particular, when a commercial sign is generally installed, a power line must be run to the sign. Running a power line is expensive; in cases where a sign is located in an area without easy access to electrical service, the cost of installing electrical service can exceed that of the sign.
Solar cells are also well known, and have been used to power commercial signs. The advantage of solar powered signs is that in many cases, the sign can be entirely powered by a solar array coupled to batteries. During the day, the solar array charges the batteries. At night, the batteries power the sign. This allows for the advantages of a commercial sign without requiring electrical service. However, prior art solar powered signs have one major disadvantage over commercial signs that operate using electrical service, which is that they are far less reliable. In particular, while proper sizing of the battery pack and solar array based on typical and worst case sunlight conditions to meet the requirements of a particular sign can guarantee sufficient power, the infrastructure typically used in solar powered signs does not provide a backup if many vulnerable components fail. For example, most solar powered signs rely on charge controllers; if the charge controller fails, then the entire circuit fails.
Accordingly, there is a need for a reliable solar power system, especially in connection with solar powered commercial signs.